Method of forming rounded bottom conical paper cups



Aug. 7, 1951 w. E. AMBERG 2,563,633

METHOD OF FORMING ROUNDED BOTTOM CONICAL PAPER CUPS Original Filed Dec. 4, 1947 3 Sheets-Sheet 1 IN VEN TOR! ATTORNEYS.

1951 w. E. AMBERG 2,563,633

METHOD OF FORMING ROUNDED BOTTOM CONICAL PAPER CUPS Original Filed Dec. 4, 1947 3 Sheets-Sheet 2 IN V EN TOR.

ATTORNEYS.

A 1951 w. E. AMBERG 2,563,533

METHOD OF FORMING ROUNDED BOTTOM CONICAL. PAPER CUPS Original Filed Dec. 4, 1947 3 Sheets-Sheet 5 INVENTOR.

Patented Aug. 7, 1951 METHOD OF FORMING ROUNDED BOTTOM CONICAL PAPER CUPS Walter E. Amberg, Beverly Shores, Ind., assignor to Lily-Tulip Cup Corporation, a corporation of Delaware Original application December 4, 1947, Serial No. 789,608, now Patent No. 2,473,840, dated June, 21, 1949. Divided and this application May 25, .1949, Serial No. 95,278

This invention relates to a method of forming paper cups of the dispensible type and of general conical form but having the bottom rounded to a substantial distance from the apex of the cone from which the cup is formed. This application is a division of my co-pending application Ser. No.*789,608 filed December 4, 1947, now Patent No. 2,473,840;

An object of this invention is to provide a method of forming a bottom to a conical paper cup of less than sixty degree'angle whereby'all substances served therein may be accessible to a conventional household spoon.

Another object of this invention is to provide a method of forming a truncated conical single piece paper cup of less than sixty degree angle having an acute angled frustro-conical side wall merging at its smaller end in a spoon serviceable bottom which may be concave or rounded. The method generally comprises circumferentially gathering the paper of an appreciable portion of the acute angled side wall at the apex end of a conical paper cup of less than sixty degree angle into the spoon serviceable bottom. The circumferential apexial gathering may be accomplished by pleating the gathered paper into a plurality of pleats, at least some of which are substantially concentrically arranged with respect to the axis of the cup. The method may also include thepreliminary step of rolling a flat sheet of paper into conical form to provide an acute angled conical side wall of less than sixty degree angle terminating in an apex before the step of oircumferentially apexially gathering the paper into the spoon serviceable bottom.

The method of forming a paper cup in accordance with this invention produces an uniformly shaped cup and maintains the strength of the paper in spite of the forming of the apexial portion of the cup into a spoon serviceable bottom.

The method of this invention is such as to produce the spoon serivceable bottom on a cup of this type without creating irregularly formed the cup when agitated by a spoon for suspending dissolvable solids in the fluid to aid in the dissolving thereof.

These and other features of this invention will 3 Claims. (Cl. 93-36-52) 1 one type of cup is formed;

Figure 2 shows a cup in the early stages of fabrication;

Figure 3 shows a cup completely formed before rounding the bottom; I

Figure 4 shows a cup mounted upon a male die in position for descent of the female die;

Figure 5 shows a cup being formed between the male and female dies;

Figures 6-11, show a cup in successive stages of formation of the rounded bottom;

Figure 12 shows a cup completely formed; Figure 13 shows a modified form of cup with rolled or beaded lip;

Figure 14 shows a fragmentary vertical section of the rounded bottom of the cup; Figure 15 shows a cup pleated with a modified form of pleat in the vertical direction; I

Figures 16 and 17 show horizontal sectionsof vertically pleated cup bottoms; 1

Figure 18 shows a vertical section of a vertically pleated cup bottom; and V Figure 19 shows a horizontal section of a vertically pleated cup bottom taken on the line l9--I9 of Figure 18.

The rounded bottom cup Dispensable paper eups'of the conical type are widely used to provide a sanitary receptacle at soda fountains, in restaurants, in work gangs, and in the home. The side walls of the cups of this type are normally formed in the shape of a cone with a very sharp apex, as the paper at the apex is usually more than one ply in thickness and brought to a firm and sharp point. This pointed cup apex notonly presents a definite hazard in the handling and use of cups of this type but also forbids the use of a spoon to remove the final content of the cup as the pointed portion of the cup remains inaccessible to a spoon and also produces vortices when the contents of the I or rounded bottom and a method of simply and uniformly forming such cups.

The accompanying drawings show a preferred form of the cup and method of its manufacture.

In Fig. 1 the cup blank 21 is shown as a familiar type such as is disclosed in my Patents Nos. 2,235,- 348 and 2,293,036. The blank may be cut from a continuous strip and is formed into a conical paper cup in the manner disclosed in the aforementioned patents by rolling the blank about a conical mandrel which moves about its apex at the point 22 so that the blank edge 23 forms the lip of the cup and the concave edge 24 forms the inner cup seam, while the straight blank edge 26 forms the outer cup seam, as shown in Figs. 2 and 3. The formed side wall of the cup is maintained as a cone by means of the adhesive strip by which the free edge of the blank is secured to the body of the cone.

The cone, as finally formed by the method to be hereinafter described, assumes the shape shown in Fig. 12 in which the conical apex of the originally formed cup has been manipulated, deformed and compressed into the rounded bottom 21, which is the characteristic novelty of this cup. The side wall of the cups becomes frustro-conical and terminates or merges at its smaller end in a rounded bottom having appreciable vertical and horizontal internal radii.

If desired, the rounded bottom may be further strengthened and the cup improved by the use of a water resistant impregnation at the cording to the manner to be pursued in forming the pleats.

One form of die for performing the method herein described is that shown, described and claimed in my copending application Serial No.

. 7,558 filed February 11, 1948.

The dies are preferably so arranged'as to form a single pleat at one time. This pleat may be either formed by simple compression dies or may be formed by spinning the conical cup about suitable mandrels so as to form the pleats successively.

lower end of the cup such as that indicated by X the numeral 28. This impregnation may be of wax or any of the so-called plastic materials which are water resistant and will readily bond to paper and can be manipulated and compressed with the paper in the method of forming the rounded bottom which is hereinafter outlined.

The impregnation may be applied to the cup blank during its process of formation or the apex portion of the completed conical cup may be immersed in the impregnation material prior to the further deformation and rounding of the cup bottom. The addition of the water resistant material not only strengthens the cup and increases its durability in use with the cup filled with liquid, but also gives the cup a smoother and more finished appearance than is possible with paper alone.

The method of forming the cup The method of forming the rounded bottom is indicated in Figs. 4-11 inclusive of the drawings and may be generally described as the formation of a series of pleats at the apex portion of the cup and then compressing this pleated portion of the cup into the rounded form of bottom desired in the final cup.

' In Fig. 4 the cup 29 is shown mounted upon a suitable conical male mandrel 30. surmounting the cup is'shown the female die member 3| with the plunger 32 about to engage the apex portion of the cup. The female and male dies are designed to form a complementary matrix, for the cup and will vary in construction ac- In Fig. 5 the dies shown in Fig. 4 have been brought together in the first stage of performing the method hereinfurther described.

In Fig. 6 the cup 29 is shown after a single application of a die to form the pleat 33 at about the line at which the rounded bottom is to be formed upon the cup.

In Fig. 7 the cup 29 has been again treated either by compression dies or by spinning, to form the second pleat 34, while in Figs. 8, 9, 10 and 11 further stages of this work are shown re sulting in the addition of successive pleats 35, 36 and 31, and as shown in Fig. 11, the final compression of the 'apex'of the conical cup at 38.

The number of pleats is immaterial but it is important that they be small so as not to bunch or pile up substantial portions of the paper cup body into small areas. 7

After the cup has been formed into the form shown in Fig. 11, a round die may be applied so as to compress the plurality of pleats into a continuous rounded bottom, asshown.

The manner in which the pleats are finally arranged in the formation of the cup bottom is shown in the fragmentary section of the cup bottom, Fig. 14, in which the successive pleats are shown folded over and compressed to form a fairly smooth, rounded cup bottom.

In Fig. 13 is shown a modified form of the paper cup in which the lip 43 has been rolled into a beaded cup lip. This beading is usually performed after the conical cup has been formed and this maybe done either before or after.

rounding of the cup bottom, as described.

zontal or circumferentially disposed, the cup bottom may be rounded by a similar method in which vertical or longitudinally disposed pleats are formed at the apex of the'cup. In either case, however, the paper at the apexial end of the conical cup is circumferentially gathered to form the cup bottom. This alternative is shown in Figs. 15-19. The cup I29 is creased vertically by suitable dies to form'the creases I33. These may be formed in various ways, such'as creasing the entire area of the apex portion. of the cup, as shown in Fig. 17. After formation of these creases the entire creased lower .end of the cup is compressd between suitable dies to round the cup bottom and form the pleats I34, shown in Fig. 19.

The method herein disclosed distributes the paper forming the cup bottomin a uniform manner and prevents the formation of crude irregularities in the cup bottom wall and weakening of the cup bottom by crushing of the irregularly distributed paper. The pleating of the paper in the manner outlined accumulates the excess paper into regular folds of fairly equal thickness, avoids any undue strain on any portion during formation, and thus strengthens the rounded bottom appreciably.

While the method of forming this cup has been described as accomplished by compression dies, it is obvious that various other means may be employed to form the step of successively pleating the portions of the cup which are to be deformed and pressed into the rounded cup bottom.

Having thus shown and described several embodiments of the invention, it is to be understood that it is capable of many modifications. For example, the spoon serviceable bottom of the truncated conical paper cup of this invention as well as being rounded may be of any other desired shape such as substantially concave for producing the beneficial results of the invention. Changes, therefore, in the construction and arrangement may be made without departing from the spirit and scope of the invention as disclosed in the appended claims, in which it is intended to claim all novelty inherent in the invention as broadly as permissible, in view of the prior art.

I claim:

1. The method of forming a spoon serviceable bottom in a conical paper cup of less than sixty degree angle comprising progressively circumferentially gathering and pleating the paper of an appreciable portion of the acute angled side wall of the conical paper cup toward the apexial end thereof, and shaping the gathered and pleated paper into a substantially transverse surface to form the spoon serviceable bottom.

2. The method of forming a truncated conical paper cup of less than sixty degree angle having an acute angled frustro-conical side wall merging at its smaller end in a spoon service- 3 able bottom comprising, sequentially radially and inwardly by a plurality of steps, circumferentially gathering and pleating the paper of an appreciable portion of the acute angled side wall toward the apexial end of a conical paper cup of less than sixty degrees angle, and shaping the gathered and pleated paper into a substantially transverse surface to form the acute angled frustro-conical side wall and the spoon serviceable bottom.

3. The method of forming a truncated conical paper cup of less than sixty degrees angle having an acute angled frustro-conical side wall merging at its smaller end in a spoon serviceable bottom comprising rolling a flat sheet of paper into conical form to provide an acute angled conical side wall of less than sixty degree angle terminating in an apex, progressively circumferentially gatheringand pleating the paper of an appreciable portion of the acute angled conical side wall toward the apexial end thereof, and shaping the gathered pleated paper into a substantially transverse surface to form the acute angled frustro-conical side wall and the spoon serviceable bottom.

WALTER E. AMBERG.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,104,535 Barbieri Jan. 4, 1938 2,220,312 Barbieri Nov. 5, 1940 2,224,129 Amberg Dec. 10, 1940 2,272,920 Merta Feb. 10, 1942 

